Electrical relay.



No. 7|2,6|9. Patented Nov. 4,1902.

A. T. M. THUMSOH. ELECTRICAL RELAY.

(Application led Feb. 4, 1901.)

(No Model.) i 3 Sheets-Sheet I.

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No. 7|2,s|9. Y Patented Nov. 4, |902. A. 1M. Tnomson.

ELEGTRICAL RELAY.

- (Application led Feb. 4, 1901.) (no nml.) 3 sheets-snm 2.

No. 7|2,6|9. Patented Nov. 4, |902.

A. T. MQ THMsoN. ELECTRICAL RELAY.

(Application med Feb. 4, 1901.)

(No llodel.) 8 Sheets-Shut 3.

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l UNITED r STATES PATENT OFFICE ARTHUR THOMAS MILNOR THOMSON, OF'THE COUNTY OF MIDDLESEX,

` ENGLAND.

mELECTRICAL RELAY.

SPECIFTCATION forming part of Letters Patent No. 712,619, dated November 4, 1902.

Application filed February 4, 1901. Serial No. 45,980. (No model.)

To @ZZ whom if; may oon/cern:

Be it known that I, ARTHURTHOMASMIL- NOR THOMSON, of No. l0 Vincent Square, in the county of Middlesex, England, have invented certain new and useful Improvements in Electrical Relays; and I do hereby declare the following to be a full, clear, and exact de-l scription of the invention, such as will enable others skilled in the art to which it appertains to make and use the saine.

The object of myinvention is to enable by means ofa single act an electrical connection i either near or Aat a distance to be established which after a certain lapse of' tiineis automatically interrupted, a second electrical con-f nection being at the same time maintained or established for a certain period. y y

My invention is especiallyapplicable to telephonie purposes, and in` particular where an automatic system of ringing telephonesubscribers bells is in use, as.it is found that the almost instantaneous operation of the au-A tomatic signal is of such momentary duration that the bells do not ring long enoughjand in some cases not at all. Electromagnets are connected in such a way with a battery or its equivalent that the,z

making of a contact by the attendant or` operator at the exchange energizes one of them.

This electromagnet when thus energized attracts its armature, and thereby makes'certain velectric contacts. connects the exchange-generator to the line, causing the subscribers bells to be rung.`

The second of these contacts connects ,the timing device above referred to to a local gal-h Vanic battery or other source of electrical power. A current from this local battery then flows through the timing device.

vertical rod or wire of metal, ebonite, orother material expansible by heat iixed at one end,

a coil of thin high-resistance wire insulated,

from .the verticalrod or wire by meansof asbestos paper, paint, or other suitable equiv One of these contacts' j The' form of this timing` device vwhich I prefer to employ consists of a movableand preferably J ondof the above-mentioned electric contacts is closedby the movement of the first of the electromagnets, as above described, the flow of current through the high-resistance wire y heats it, and the heat being communicated i from it tothe vertical rod or wire causes the latter to expand. The upper end of the rod or wire by this expansion is adapted to move a lever, which may be bent or hinged, or a eXible piece of metal or the like equivatrical contact, which is made by the movement produced by the expansion of the vertical rod. The heating of this coil of wire :and the consequent expansion of the met-al irod require time. This period of time may l be arranged to suit the requirements of each l individual case. When this third contact is made by the action of the heating appliance, it throws a second electromagnet into parallel with the irst. This second electro- 3 magnet is not energized until the metal rod of the above-described thermostatic timing device by expanding makes a contact and atltractsits `own movable armature, which on being attracted breaks a contact in series with the first of the electromagnets already L mentioned, through which the current which energized it has up to that instant been flowing, and thereby -disconnects the said Iirst jelectromagnet from the circuit, while at the Sametime it makes a fifth electric contact, which has the eect of permitting thecurrent to continue iiowing through the coils of the second electromagnet and to continue engergizing it as long as the line is in use. When 'the first of the electromagnets is thus thrown out of circuit by the operation of the second, it of course releases its armature. This intor and the subscribers bell (which thereupon stops ringing) and also disconnects the batfore is, when the connection is made at the start and continue ringing until the timing device has heated up and made the contact which the movable portion or' it carries. The generator is then cut out, and the bell stops ringing. l

InV` order that-the nature of this invention lent device capable of carrying a third elec? gterrupts the connection between the generatery from the timing device. The eect thereexchange, to cause the subscribers bell to IOO may be the more readily understood, I hereby referto the accompanying drawings, which I also at the same time make part of the present specification.

In the drawings, Figure l represents diagrammatically the component parts and the electrical connections employed when the time interval during which the calling bell shall ring is determined by an electric thermostatic device. views of an alternative construction, in which the requisite time interval is occupied in effecting a definite movement from rest of a clockwork mechanism; and Figs. 5 and 6 show a fn rther alternative timing device, in which the interval is occupied in effecting a definite movement from rest of an electromotor.

In the diagrammatic drawing of Fig. l, M and M' are the electromagnets, provided, respectively, with the armatures a and a', held in normal position by suitable means, such as the helical springs n and n', attached to a fixed arm p at one end and to adjustable screws o and o", mounted in prolongations of the armatures a and a', respectively. A second prolongation of the armature a at its other extremity carries apwedge Z9 of insulating material, adapted to pass between the curved ends of the liexible metallic springs or arms CZ and CZ, secured in the block of insulating materiale, to which likewise are attached the contact-springsffinthemannershown. This second prolongation ot' the armature ct likewise carries a rounded wedge or roller ot insulating material c, adapted to slide upon the bent end of the contact-spring h and displace it axially. The armature c of the electromagnet M carries a contact-spring t, which normally makes contact with the contact K', butis likewise capable 'of and adapted to make contact with the contact Kzat the end ot the contact-springj.

gis the line-wire high-resistance coil of the heating timing device,which is coiled, as seen, on the vertical rod fr. This vertical rod r is lixedly secured to the blockm and carries at its `top the block of insulating material m'. The bent rod or spring q, secured at q', reposes on 'm'. The heating-coil of this appliance is connected to one pole of the local battery B' by the lead Z2, the other end ofthe said coil g being connected to the contact-spring hrby the lead Z3. The other pole ot' the battery B' is connected to the adj nstable contact K3. G is the generator, which is connected by the leads Z7 and Z8 to the contact-springs d OZ, the contact-springs ff being connected by the leads Z and Z' to the two sections PZ and PZ' of the plug P, thesection Pc of this same plug P is connected to the two electrom agn ets M and M' by means of the lead Z5.

The remaining cennections of the electromagnets and the other parts, which are shown in the drawings in their positions of repose or the positions they usually occupy when the apparatus is not in use, are as follows: The electromagnet M is connected to the section Figs. 2, 3, and 4- are three.

Pc of the plug by the lead Z5, as already explained. The other end of the winding of the electromagnet M is connected by the lead Z" to the adjustable contact K', the electrical connection extending farther through the spring t' and the lead Z9 to earth at E'. The lower end ofthe winding ofthe electromagnet M' is connected tothe contact-springj. The jack J has two contact-springs s and s', connected to the line-wires L and L', while its bush C is connected to one pole of the station-battery I3, the other pole ot which is earthed at E.

It will be understood that the connections to the plug P are inrpart tiexible connect-ions to enable it to be inserted into the jack J.

The function ot the apparatus is as follows: Vhen the plug Pis inserted into the jack J, the section Pc making contact withthe bush C causes the electromagnet M to be energized. The current passes from the unearthed pole of the battery B by Way of the lead Z5 to the electromagnet M, thence by way of the lead ZG, the contact K', the spring t' and the lead Z9 to the earth at E', and thus completes the circuit. The electromagnetMthereupon attracts its armature ot, the movement of which produces two results-first, the Wedge b by separating the contactsprings CZ d and causing them to make contact with ff, puts the generator Gr into electrical connection with the line-Wires L and L' by way of the leadsZ and Z', the sections PZ and PZ', and the springs s s', thereby causing the bell of the subscriber who is being called to ring; secondly, the spring h by making contact with the stud K3 completes thecircuit ofthe battery B' through the thermostatic device above referred to. The current from this battery passes through the high-resistance wire g, heating the same, and giving rise to the gradual expansion of the rod r, with the result that the displacement of the contactspring q causes it to make contact with K4. When contact between q and K4 is established, the electromagnet M' becomes energized, the current from the battery B passes from C through the lead Z5, through the electromagnet M' and the lead Z4 to the contact K3, thence through contact-spring q and the lead Z9 to earth at E'. The armature ct' is consequently attracted, therebycausing the contact-spring c' to break contact with the stud K'` and to make contact with the stud K2 at the end of the contact-springj- This, as will be seen, breaks the circuit of the electromagnet M, which therefore releases its armature al, with the result that the connections between the generator G and the line are broken by the withdrawal of the Wedge b from between the contact-springs d OZ, and 'the subscribers bell consequently stops ringing. Contact between K3 and the spring Zt is also broken, interrupting the circuit of the battery B' at the point K3. The coil g being no longer supplied with current cools down, and the rod r by contracting causes the spring q to gradually revert to its normal position.

IOO

IIO

twill be understoodfrom the nature of the i thermostatic device that contact is not'estab-` lished between q and K4 until an appreciable time has elapsed since the insertion of the plug intothe jaclgso that by adjusting this` time constant of the device the length of time during which the subscriber-s hell continues to ring may be varied at will. As, however, contact has been made between the spring 'Z and the springj at K2, the magnet M still continues to be energized as long as the plug P is in the jack, its circuit being in that case completed `through the spring j, the spring fi, and the lead J to'the earth at E. When, however, the plug is tin-ally withdrawn from the jack, the section Pc being no longer in electrical contact with the ring or bush C, the magnet M loses its energy, and its armature returns to the position shown in the drawings, in which condition the apparatus is ready towoperate again on the insertion of the plug into the jack J.

Instead of the time occupied iu ringing being depended on and defined by the necessary interval requisite to heat and expand a given piece of material it may be determined by the interval required by a force derived from the attraction of an armature to generate momentum in a revolving fan through a clockwork mechanism and e'iect a delinite change of position. Figs. 2, 3, and 4 represent three views ot this apparatus, the lead of the wires andthe connectionsbeing shown diagram matically. Parts which correspond to Fig. l are similarly lettered and numbered. In this case the coils of both electromagnets M and M are connected to wire Z5, so that both are energized at the same time, the circuit around M being connected `directly to earth at E2, while that around M is led to earth at E through a spring-contact K', as in Fig. l. The Wedgingof b between the springs OZ completes the circuit through the generator and bellas before, and the attraction of the armature a" starts a clockwork mechanism into motion in the following manner: At the end of the armature there is a spring-pressed pawl a2, which engages with the teeth of a crown ratchet-wheel in its movement from right to left. ,The ratchet-wheel is in one with a toothed Wheel which gears with a pinion which is a part of a spindle carrying a gear-wheel as', which gears withasecond pinion which forms a part of a spindle on which a fan y is mount- 'ed. The attraction of the armature starts the fan into motion, permitting the armature to move in obedience to the force. Aftera certain amount ot movement the contact between the .spring 't' and the screw K will be broken and the magnet become denergzed. The consequent withdrawal of "the Wedge Z9 will throw the generator out of circuit with the line-wires, and the signal-bell will cease to ring.

A further alternative method of determining the length of time during which the signal-bell should ring is shown in Figs. 5 and 6,

inwhich an electrolriotoris started into motion, and after a certain movement acontact is made which stops the ringing of the bell. The operation intimately resembles that of Fig. l. `Corresponding parts are correspondingly lettered, and the leadof the wires and the situation of the contacts are` shown diagram matically. The electromoto'rz is constructed with three pole-pieces, so as to be self-starting in any position. It is energized bythe battery B' when thecircuitI is completed by the contact of the spring h with K3. The motor is, in fact, interposed between the wires Z3 and Z2 instead of the high-resistance helix of Fig. `1. The motor drives a iiy-wheel W by a worm tu, engaging with teethformed on the face of W. There `is a projection q on the rim of W, which on contact with the spring named K4 causes the same oftice to be performed as thelike-named parts of Fig. 1- that is to say, the magnet M becomes energized and M decnergized-so that the bell which commences to ring when the motor is started ceases ringing when q and K4 make contact.

I claim- 1. A combination of `two combinations of electrical and mechanical devices adapted to effect the object of calling subscribers through telephone-exchanges for an automaticallylimited period of time of which one combination consists of a constantly-working generator, a relay-magnet and armature, a battery, a plug, switch-jack, spring-contacts and wire connections to subscriber, these elements being so disposed and adapted that the insertion of the plug in the jack completes alocal circuit through the battery and relaymagnet, the armature of the latter being adapted to completea circuit through the generator and the subscribers` wires: the other combination comprising a second relay-magnet and armature and a time-expending device containing a moving part which is urged by electric energy switched 1in by the iirst combination and which is adapted to break the local circuit established by the plug and jack of the first combination.

2. A combination 'of two combinationsof electrical and mechanical devices adapted to effect the objectof callingsubscribers through telephone-exchan ges for an automatically-limited period of time of which one combination consists of a constantly-working generator, a relay-magnet and armature, a battery,a plug, switch-jack, spring-contacts and wire connections to subscriber, these elementsbeing so disposed and adapted that the insertion of the plug in the jack completes a local circuit through the battery and relay-magnet, the

armature of the latter being adapted to complete a circuit through the generator and the subscribers wires: the other combination comprising a second relay-magnet and armature, a second battery, a rod, a high-resistance coil, wire connections and contacts and the armature of the iirst-mention edrel'ay-mag- IIO net the latter being;` adapted to complete a local circuit through the second battery and high-resistance coil which latter is so disposed as to heat the rod which latter is adapted to complete a circuit through the second relaymagnet whose armature is adapted to break the local circuit established by the plug and jack of the first combination.

3. In combination with a device adapted to eect the object ofcallingsubscrib'ers through telephone-exchanges. for an automaticallylimited period of time,a furtherdevice,adapted t0 prevent an unintentional repetition of the calling-signal by providing an alternative circuit through the battery and relay-magnet which causes the termination of the period ARTHUR THOMAS MILNOR THOMSON.

Witnesses:

F. W. LANE, W. M. HARRIS. 

